Analysis & Opinion

NEW YORK (Reuters) - The U.S. dollar gained broadly on Monday on lingering concerns about euro-zone debt, while speculation of further monetary easing by the U.S. Federal Reserve boosted Treasuries prices.

U.S. and European stocks fell as tighter banking capital rules imposed by Swiss policymakers reminded investors of potential troubles in the European banking system.

Japan was also headed to a negative start, as Nikkei futures traded in Chicago fell 120 points to 9,350.00.

Worries about euro zone economies were again in the spotlight, adding pressure to the euro, after the Irish central bank said Ireland's economy will crawl to a virtual halt this year. Investors were also cautious about the implementation of more austerity measures in Portugal.

"The euro has come a very long way in a very short period of time, and certainly Ireland and the peripheral euro zone country issues have not gone away," said Omer Esiner, chief market analyst at Commonwealth Foreign Exchange Inc in Washington. When those issues "come back in the spotlight, they are used to take some profits on the euro."

Analysts added, however, that the trend of a weakening dollar remains intact.

The European single currency weakened 0.80 percent against the dollar to $1.3678.

Euro zone concerns also bolstered the dollar against other major currencies. The U.S. Dollar index .DXY rose 0.50 percent despite expectations of additional monetary easing by the Fed, which tends to be negative for the greenback.

Against the Japanese yen, the dollar was up 0.25 percent at 83.40.

Gold prices retreated slightly as the dollar rose. Spot prices for the metal fell 0.24 percent to $1,314.00 an ounce, close to Friday's all-time high of $1,320.80.

Gold prices have been soaring recently as investors see it as a safe-haven alternative to a weakening dollar.

"Gold is holding up comparatively well considering the rebound in the U.S. dollar," said David Thutell, an analyst at Citigroup. "I suspect that for many months there will be enough market participants who don't buy the recovery story and will keep buying gold."

Speculation that the Fed will eventually resume quantitative easing to support the economy, probably by purchasing more government bonds, sent yields on two-year Treasury notes to a record low of 0.4 percent in overnight trading.

The 10-year Treasury notes traded 8/32 higher in price to yield 2.48 percent, down from 2.52 percent late on Friday.

TIGHTER BANK RULES

Key stock indexes slid in the United States and Europe as the dollar weakened, weighing on prices of raw materials and commodity-related stocks in general.

A decision by Swiss regulators to require UBS AG (UBS.N)UBSN.VX and Credit Suisse (CS.N)(CSGN.VX) to hold far more capital than their international rivals also weighed on bank stocks.

The rules, aimed at preventing a banking crisis in Switzerland, could crimp competitiveness in investment banking.

"These austerity measures are necessary but don't have a stimulating effect on the market," said Malcolm Polley, president and chief investment officer of Stewart Capital Advisors in Indiana, Pennsylvania.

Oil prices were little changed after a rally of more than 6 percent last week. U.S. crude prices settled down 11 cents, 0.13 percent, at $81.47 a barrel.

After Latin American markets closed, Brazil announced it was doubling to 4 percent a tax on foreign investment into domestic fixed-income assets, as part of a bid to curb the appreciation of the real.

The measure should reduce currency gains in the short term, while making Brazilian government bonds less attractive to foreign investors, analysts said. Part of the inflows could be diverted to other Latin American countries such as Mexico or Colombia, forcing them into similar measures.